This tests that exceptions in setTimeout triggers 'worker.onerror'.
On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
Page-level worker.onerror handler triggered:
PASS errorEvent.message is "Uncaught Error: Exception in setTimeout callback"
PASS stripURL(errorEvent.filename) is "[blob: URL]"
PASS errorEvent.lineno is 3
FAIL errorEvent.colno should be 19. Was 13.
PASS errorEvent.error is null
PASS successfullyParsed is true
TEST COMPLETE